<template>
  <view>
  <up-popup :show="previewShow" @close="previewClose" mode="center" :closeable="true">
  <view class="previewImage" :style="{ 'background-color': 'rgba(0,0,0,' + opacity + ')' }" v-if="show" @tap="close" @touchmove.stop.prevent>
      <!-- 加载中提示 -->
      <view class="loading" v-if="loading">
        <text class="loading-text">加载中...</text>
        <image class="loading-icon" src="/static/loading.gif" mode="aspectFit"/>
      </view>
      <swiper class="swiper" :current="index" @change="swiperChange" :disable-touch="swiper" :circular="circular">
        <swiper-item v-for="(img, i) in imgs" :key="'swiper-item-'+i" :id="'swiper-item-'+i">
          <movable-area class="marea" scale-area>
            <movable-view
                :id="'movable-view-'+i"
                :key="'movable-view-'+i"
                class="mview"
                direction="all"
                :out-of-bounds="false"
                :inertia="true"
                damping="90"
                friction="2"
                scale="true"
                scale-min="1"
                scale-max="4"
                :scale-value="scale"
                @scale="onScale"
                @change="movableChange"
            >
              <image
                  :id="'image-'+i"
                  :key="'movable-view'+i"
                  class="image"
                  :src="img"
                  :style="{ transform: 'rotateZ(' + deg + 'deg)' }"
                  :data-index="i"
                  :data-src="img"
                  mode="widthFix"
                  @touchmove="handletouchmove"
                  @touchstart="handletouchstart"
                  @touchend="handletouchend"
                  @load="onImageLoad"
                  @error="onImageError"
              />
            </movable-view>
          </movable-area>
        </swiper-item>
      </swiper>
      <view class="page" v-if="imgs.length > 0">
        <text class="text">{{ index + 1 }} / {{ imgs.length }}</text>
      </view>
<!--      <view class="save" v-if="saveBtn" @click.stop.prevent="save"><text class="text">保存</text></view>-->
<!--      <view class="rotate" v-if="rotateBtn" @click.stop.prevent="rotate"><text class="text">旋转</text></view>-->
      <view class="desc" v-if="descs.length > 0 && descs.length == imgs.length && descs[index].length > 0">{{ descs[index] }}</view>

  </view>
  </up-popup>
  </view>
</template>

<script>
export default {
  name: 'ksj-previewImage', //插件名称
  props: {
    imgs: {
      //图片列表
      type: Array,
      default: () => {
        return [];
      }
    },
    descs: {
      //描述列表
      type: Array,
      required: false,
      default: () => {
        return [];
      }
    },
    //透明度,0到1之间。
    opacity: {
      type: Number,
      default: 0.8
    },
    //保存按键
    saveBtn: {
      type: Boolean,
      default: true
    },
    //旋转按键
    rotateBtn: {
      type: Boolean,
      default: true
    },
    //循环预览
    circular:{
      type: Boolean,
      default: false
    }
  },
  data() {
    return {
      swiper:false,//是否禁用
      show: false, //显示状态
      index: 0, //当前页
      deg: 0, //旋转角度
      time: 0, //定时器
      interval: 1000, //长按事件
      scale: 1, //缩放比例
      loading: true, // 新增 loading 状态
      previewShow: false, // 预览弹窗显示状态
      currentPreviewIndex: 0, // 当前预览图片索引
      previewList: [] // 预览图片列表
    };
  },
  created() {
    this.loading = true
  },
  onUnload(){
    this.loading = true
  },
  methods: {
    onImageLoad(e) {
      this.loading = false; // 图片加载完成后隐藏 loading
      // console.log('图片加载完成', e);
    },
    onImageError(e) {
      this.loading = false; // 加载失败也隐藏 loading
      // console.error('图片加载失败', e);
    },
    //比例变化
    onScale(e) {

    },
    previewClose(){
      this.previewShow = false
    },
    //长按事件相关内容---------开始-------------------
    //接触开始
    handletouchstart(e) {
      var tchs = e.touches.length;
      if (tchs != 1) {
        return false;
      }
      this.time = setTimeout(() => {
        this.onLongPress(e);
      }, this.interval);
      return false;
    },
    //清除定时器
    handletouchend() {
      clearTimeout(this.time);
      if (this.time != 0) {
        //处理点击时间
      }
      return false;
    },
    //清除定时器
    handletouchmove() {
      clearTimeout(this.time);
      this.time = 0;
    },
    // 处理长按事件
    onLongPress(e) {
      var src = e.currentTarget.dataset.src;
      var index = e.currentTarget.dataset.index;
      var data = { src: src, index: index };
      this.$emit('longPress', data);
    },
    //长按事件相关内容---------结束-------------------

    //图片改变
    swiperChange(e) {
      const currentIndex = e.detail.current; // 使用 detail.current 获取当前索引
      if (typeof currentIndex === 'number' && !isNaN(currentIndex)) {
        this.index = currentIndex; // 更新当前图片索引
        this.loading = true; // 重置 loading 状态
        this.$nextTick(() => {
          this.scale = 1; // 重置缩放比例
          this.loading = false;
        });
      } else {
        console.error('Invalid index:', currentIndex);
      }
    },

    //移动变化
    movableChange(e) {
      //console.log(e);
      /* if(this.old.scale <= 1){
        this.swiper=false;
      }else if(e.detail.x===0){
        this.swiper=false;
      } */
    },


    //保存
    save(e) {
      var _this = this;
      var src = this.imgs[this.index];
      //#ifdef MP-WEIXIN
      //提前向用户发起授权请求
      uni.authorize({
        scope: 'scope.writePhotosAlbum',
        success() {
          console.log('kxj-previewImage:允许储存');
          _this.downloadImg(src);
        }
      });
      //#endif

      //#ifdef APP-PLUS
      this.downloadImg(src);
      //#endif

      //#ifdef H5
      //非同源图片将直接打开
      var abtn = document.createElement('a');
      abtn.href = src;
      abtn.download = '';
      abtn.target = '_blank';
      abtn.click();
      //#endif
    },

    //下载并保存文件
    downloadImg(src) {
      //下载图片文件
      uni.showLoading({
        title: '大图提取中'
      });
      uni.downloadFile({
        url: src,
        success: function(res) {
          console.log('kxj-previewImage:下载成功');
          uni.hideLoading();
          uni.saveImageToPhotosAlbum({
            filePath: res.tempFilePath,
            success: () => {
              uni.showToast({
                title: '已保存至相册',
                duration: 1000
              });
            }
          });
        },
        fail: function() {
          uni.hideLoading();
          uni.showToast({
            title: '图片下载失败',
            icon: 'none',
            duration: 1000
          });
        }
      });
    },

    //旋转
    rotate(e) {
      this.deg = this.deg == 270 ? 0 : this.deg + 90;
    },
    //打开
    open(e) {
      if (e === null || e === '') {
        // console.log('kxj-previewImage:打开参数无效');
        return;
      }

      if (!isNaN(e)) {
        if(e>=this.imgs.length){
          // console.log('kxj-previewImage:打开参数无效');
        }else{
          this.index = e;
        }
      } else {
        var index = this.imgs.indexOf(e);
        if(index===-1){
          this.imgs = [e];
          this.index = 0;
          // console.log('kxj-previewImage:未在图片地址数组中找到传入的图片，已为你自动打开单张预览模式')
        }else{
          this.index = this.imgs.indexOf(e);
        }
      }
      // console.log('kxj-previewImage:当前预览图片序号'+this.index);
      this.show = true;
      this.previewShow = true
    },
    //关闭
    close(e) {
      this.show = false;
      this.previewShow = false
      this.index = 0; //当前页
      this.deg = 0; //旋转角度
      this.time = 0; //定时器
      this.interval = 1000; //长按事件
      this.scale = 1; //缩放比例
      this.loading = true; // 重置 loading 状态
    }
  }
};
</script>

<!--使用scss,只在本组件生效-->
<style lang="scss" scoped>
.previewImage {
  z-index: 999;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: #000000;
  user-select: none;
  .swiper {
    width: 100%;
    height: 100%;
    .marea {
      height: 100%;
      width: 100%;
      position: fixed;
      overflow: hidden;
      .mview {
        display: flex;
        align-items: center;
        justify-content: center;
        width: 100%;
        height: auto;
        min-height: 100%;
        .image {
          width: 100%;
        }
      }
    }
  }

  .page {
    position: absolute;
    width: 100%;
    bottom: 40rpx;
    text-align: center;
    .text {
      color: #fff;
      font-size: 26rpx;
      background-color: rgba(0, 0, 0, 0.5);
      padding: 3rpx 16rpx;
      border-radius: 20rpx;
      user-select: none;
    }
  }
  .save {
    position: absolute;
    left: 10rpx;
    /*  #ifdef  H5  */
    width: 120rpx;
    bottom: 20rpx;
    /*  #endif  */
    /*  #ifdef  APP-PLUS  */
    width: 220rpx;
    bottom: 40rpx;
    /*  #endif  */
    height: 56rpx;
    text-align: center;
    padding: 10rpx;
    .text {
      background-color: rgba(0, 0, 0, 0.5);
      color: #fff;
      font-size: 30rpx;
      border-radius: 20rpx;
      border: 1rpx solid #f1f1f1;
      padding: 6rpx 22rpx;
      user-select: none;
    }
    .text:active {
      background-color: rgba(100, 100, 100, 0.5);
    }
  }
  .rotate {
    position: absolute;
    right: 10rpx;
    /*  #ifdef  H5  */
    width: 120rpx;
    bottom: 20rpx;
    /*  #endif  */
    /*  #ifdef  APP-PLUS  */
    width: 220rpx;
    bottom: 40rpx;
    /*  #endif  */
    height: 56rpx;
    text-align: center;
    padding: 10rpx;
    .text {
      background-color: rgba(0, 0, 0, 0.5);
      color: #fff;
      font-size: 30rpx;
      border-radius: 20rpx;
      border: 1rpx solid #f1f1f1;
      padding: 6rpx 22rpx;
      user-select: none;
    }
    .text:active {
      background-color: rgba(100, 100, 100, 0.5);
    }
  }
  .desc {
    position: absolute;
    top: 0;
    width: 100%;
    padding: 5rpx 10rpx;
    text-align: center;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    background-color: rgba(0, 0, 0, 0.5);
    color: #fff;
    font-size: 28rpx;
    letter-spacing: 3rpx;
    user-select: none;
  }
}


.loading {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 1000;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 999;
}

.loading-text {
  color: #fff;
  font-size: 28rpx;
  margin-bottom: 10rpx;
  background-color: rgba(0, 0, 0, 0.5);
  padding: 10rpx 20rpx;
  border-radius: 10rpx;
}

.loading-icon {
  width: 60rpx;
  height: 60rpx;
  animation: rotate 1s linear infinite;
}

@keyframes rotate {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

</style>
